I'm trying to do a design and cost work-up for an HD projector capable of 720p and 1080i with pretty much all the input possibilities, but I am extremely new to anything like this and feel completely lost without a starting point. Could anyone give me a push in the right direction? I would greatly appreciate it.

As far as LCDs and Controllers, you might want to check out what member johnzo has to offer at his external website store.

If that's too expensive for you, then the next step would be to investigate using a less expensive widescreen LCD TV. If you're really wanting 1080p, you can use the following Google link to research these types of builds on LL.

Google: site:lumenlab.com +lcd +tv +1080p

Oh... and as always, the best place to start is with the basics: The Lumenlab PRO DIY Projector Guide V.3

Sheesh! - Where are my manners?

Welcome to the forum and welcome to the soul-eating "hobby" of DIY projector building.

There seems to be only one thing missing from all of the controllers I have seen for an HD diy projector and that is having an ATSC tuner built in, all the ones I have seen on here that have a tuner are not HD (ATSC) tuners, so if that it a prerequisite than you might have to make sure you have a HTPC with a HD tuner card in it.

I found a flat-panel 15 inch LCD tv with all of my requirements for $200 today at Best Buy, so if I use that, do I even need a controller?

The controller is what feeds the lcd, as this tv can produce a picture I'd say no. btw have a modle number?

If you check out the Google link I provided, you see how others adapted their LCD TVs for use in a projector.

In short, the LCD TV does have a controller board (the board that contains all the inputs as well as the OSD menu board) just like any LCD monitor would have. As mentioned above, a make and model number (or even a link to the product page on BB's site) would be helpful.

lostterminal: is this the one you found at best buy?

I don't know man, I checked best buy online and thats the only 15" they claim to be a 720p LCD tv.

I really dislike when a company advertises a product to be 720p when it is a 1024 x 768 resolution, thats not 720p, 720p is 1280 x 720 resolution.

It's a Pyle PTC15LC tv.

And it's 1024x768, so I guess I'll have to move up to a 17 incher to get 720p?

Are you unable to see my posts, or what?

If you had clicked on the Google link above, you will see that there are plenty of 15.4 HD (at least 720p) LCD TVs that you can purchase for around $200 - $250.

Here's one for $229.99 from Circuit City: http://www.circuitcity.com/rpsm/oid/175557...il.do#prodspecs (Tuner type: NTSC, ATSC)

The only problem with the 15.4 LCDs is that I don't know what I'm doing here, and having to cut fresnels down to size is kind of out of my league.

The only thing you need to remember when cutting fresnels is to cut them equally on both sides. For example, If your fresnel is two inches wider than it needs to be, you will have to cut one inch off of the left side and one inch off the right side. It's the same for top and bottom. You can score a line on the side of the fresnel that does not have grooves and then snap it along the scored line.

But, you don't even have to cut the fresnels. That's only done if you want to minimize the size of your enclosure.

I can find a tutorial on LL here, if you'd like.

Here you go: Cutting Fresnel Lenses

And more information.

eww dude Pyle (of poop) stay away!

Here's a Polaroid 15.4" LCD HDTV (720p) from Circuit City, too (Built-in tuner: NTSC/ATSC).

A thumbs-up from a LL member.

Here's a search on the LL site for more information on the Element LCD TV: site:lumenlab.com +FLX +1510

Ok, so assuming I can do everything without permanently destroying one of the parts, and including shipping and the cost of the tools I will most probably need to use, I'm looking at around $760 dollars if I buy everything new. And I can't find the screen used yet.

I can under stand trying to keep costs down, however you will pay for HD quality - so realize that. Now look up how much HD comerc pj are going for - 3 & 4k. Take yer time, dont rush it.

Plus, the good thing about building one, is that I can buy the parts in progression and not have to worry about dropping that load of money all at once.


As far as designs are concerned, I'm wanting to make a coffee table design like Moose's, but put it on desk wheels, since I may have to move it between rooms, and then cut a hole in either door so that I can watch the screen with the doors close. Plus, since this is really going to be a gaming and movie projector, I can store all that stuff in the sides of the table. I'm going to install autocad again and see if I can work up a design tonight after work.

Actually for the res he is looking for, commercial projectors are pretty cheap, but there is always that one little feature that every one is looking for when they build there projectors, that they can't find in a commercial projector whatever that maybe, be it 1080p at a decent price, inexpensive replacement bulbs or in the case of lostterminal he says coaxial input so I assume he is looking for a built in tuner, which I have yet to see in any commercial projector.

Like many have said take your time and do your research.

The two things I need that the inexpensive PJs don't have are like SilentReaper said; the coaxial input and an HDMI input. I can find a commercial PJ that has component and composites and have the resolutions I need, but not the tuner or HDMI, for about $500-$600. This way, I can get all the connectors I'll ever need.

Also, I was wondering if the remote for the TV would still work on the projector once this is done.

Yes, as long as you incorporate the IR sensor. It's basically the same TV, just disassembled.

Does the Focal Calculator help determine how long the PJ case needs to be? I'm not sure I understand what everything means, and when I try to find certain values based around a 15.4 screen, they come out with reall small decimal numbers for screen size and such.

Also, you mentioned a polaroid tv before, what about this one?
http://www.target.com/Polaroid-15-4-LCD-Te...4499&page=1
I get an discount for this one because I work for Sprint.

Your choice of lenses determine the length of your enclosure. For me, I'm using 220/320 fresnels and a varifocal triplet. This tells me that my distance from the LCD to the triplet will have to be around 320mm (+/- 20mm). I also know that, due to the 220 FL of my rear fresnel, the distance from my lamp arc to LCD will need to be around 220mm (again, +/- 20mm). If possible, you want to allow for adjustment of the distance from triplet to LCD via some type of focusing mechanism. In the same manner, you might want to allow for some adjustment in the distance from the LCD to the lamp's arc by making the bulb mount adjustable.

When you plug your numbers into FocalCalc, you plug in your "known" numbers and it'll churn out your "unknowns". So far, the only known numbers you've given are the 15.4 diagonal LCD. What diagonal screen size are you looking for? What would be the minimum and maximum distance from triplet to screen? Have you decided to go with LL's Pro lenses? If you provide your known numbers, I'll show you what they look like when plugged into the FocalCalc.

A search of the LL Forum for 01511C (the Polaroid).
Somebody mentioned that it appears to be the same LCD TV as the Element. Mind you, I have no experience with any of these.

Ok, that polaroid from target is going to run me 224.04 after taxes and shipping and handling.

I'm looking for a 96 inch display with a 15.4 inch LCD, of course. I'm not sure what the difference between split and un-split are, except once has 2 fresnels and the other has one. do I need the pro lenses? What will it improve?

For now, I just used the fresnel lenses that come with the S15 mega kit.

I crunched the numbers, and it looks like the pro lenses add $167 to my project costs... So I just need to know if it is worth it.

Okay... this is where you be disappointed.

Your FocalCalc shows that the distance from triplet to screen is almost 7 feet. You'll want to go with a split fresnel setup so that you can keystone the front fresnel so your image is projected on the screen properly. Keystoning only allows for something like a 5 - 15 degree angle off-axis to being perpendicular to the center of the screen. With your projector only 7 feet from the screen, you'll be sitting behind the projector. This means that the projector will be in your line of sight and will be blocking your view of the screen.

You'll want to go with a different triplet and front fresnel for your projector.

Oh... I forgot to mention. Your triplet will need to be about the same focal length as your front fresnel.

Using a 15.4 LCD, your enclosure is going to have to be about 3 feet long (if it's a horizontal, straight shooter) or 3 feet tall (if it's a vertical). You can decrease the size of the box buy building a folded design.

If I was going to build with a 15.4, I'd do it like arkcom did.

As far as the projector being in sight, I wasn't too worried about that, since I was hoping to put it in a coffee table like Moose's. But the vertical design might even be better, because I'd rather the table be about 3 feet high than 3 feet deep.

I always get that wrong.
It's the unsplit setup that would be blocking your view.

Did moose make any mention of the FL of the fresnels he was using?

"Is the pro lens worth it"

Well, that depends on you and your goals.

For me, hands down, it is. My standard lens build stood on stilts to be situated about 4' off of the ground. This was needed so that I could use minimal keystoning, since any signifigant amount of keystone correction proved untenable for me. My seat ended up being right beside the projector, because if I was closer, the screen was too big to watch comfortably, and if I was further, the projector was in my way.

The pro lens projector sits well behind the seating area. This keeps it out of the way, gives more option for seating position, and generally makes the whole experience far more enjoyable.

I'm fairly certain he used 220mm and 317mm fresnels, though he doesn't explicitly say.

Supra, did you use split or unslpit? How well does split fresnels correct keystoning?

The 317mm fresnel that LL sells is for a panel that is 15" or less. (jonjandran always jumps on me for saying this)

If you're looking to use the Pro lenses from LL, here's what you're looking at:

For a 96" diagonal widescreen projection (remember, you're dealing with a widescreen LCD):



This next one shows the screen size (using the Pro lenses) when the triplet is moved to 7 feet from the screen:

Okay... here's a compromise, if you can live with it:


http://www.lumenlab.com/forums/index.php?s...st&p=272442

Unfortunately, I don't have 12 feet to work with here...

I think the above compromise will only work right if the projector was sitting on top of a coffee table - due to needing to keystone.

what if I have a vertical design like Arkcom has with just the lens above the coffee table surface?

Sorry for the crude images, but I'm at work, and only have access to mspaint.





Do you think that could work?

Ok, so back at home, working with CadStd, I came up with a little more sophisticated, but still estimated design for what I'm thinking of.



Please tell me what you guys think, since you know far more than I do about what will and will not work.

Hopefully this will help fix keystoning, while still keeping a low profile.

Will the compromised fresnels affect my image quality at all?

That's a nice idea, but...

Have you taken out a tape measure and measured 30" up from the floor?
That's a pretty tall coffee table. Your typical coffee table is about 18" tall. I'm not trying to dissuade you from building it, but something that tall would be better suited to an end table design.

To give you an idea what the center projector area would look like, size-wise, it would be like having TESCORP's V-15 sitting in front of your viewing area:



You'll notice that it's not so bad when placed between chairs... but that takes away from what I call the "cuddle factor". Maybe have it just behind the seating area as sort of a sofa table. You know, those tall tables that sit behind a sofa. Even if it ends up being sandwiched up against a wall by the sofa, as long as you've got adequate ventilation, you should be fine. And you'll have a nice surface back there to put stuff on.

Also, you won't be able to throw your projected image at an angle, like that. The projected image will be half above and half below the perpendicular line from the triplet. What you're showing there is lens shifting and that's a whole 'nuther ball o' wax.

Well, since I only have a one-bedroom apartment, and the living room is fairly small, I was going to put the projector trunk at the foot of my bed, and have the whole projector tilted up slightly to make the image above where the projector would be in the way. Unfortunately, I can't suspend anything from my ceilings, and I don't have enough room anywhere to keep the projector 12 feet away without suspending it.

So I'm not looking for a large throw distance, but would like to make sure quality is maintained.

One way of doing a project like this in a coffee table but achieve the 3' lift would be to do something like a tilt up section. That is to say have a section of the top of the table that is hinged on the back edge and the front lifts up to give the required 'height' for the lense. You would then need to project back towards the rear of the table, reflect through 90 degrees up to a second mirror and that would project forward through the lense and onto the screen. I hope that makes sense.

Another method is to use a stereo cabinet or small bookcase an d fit the projector into that.

Hi, here is a very rough sketch for you.



It may be a bit clearer, well a little.

I see what you mean, but part of the allure of doing the design like this is that I also have storage for all the things that will be connected into the projector right there in the same peice of furniture.but I may try just having a mirror pop-up at the back of the trunk but still keep mostly the same dimensions.

Mate, you could have a section of the lid that lifts with the lense, either at the end or in the middle and have the other sections to store the other goodies. Best of both. Anyway just an alternate idea for consideration.

How about a floor plan of the room the projector will be in - including measurements and door/window placement. You mentioned it will be a bedroom. Perhaps dimensions of furniture, as well.
I'm guessing that the "seating" will be on the bed, itself.

I got it I got it.
Short throw rear projection onto the other side of a screen hanging at the end of your four post bed.
cozy

Nevermind. Im a jerk... hehe

The room is 12' by 16' roughly, and the door an window placement kind of hinder screen placement.



I can move the bed around, it's a queen, so it's 5' by 6' 8", but it seems no matter where I can move it, the bed won't be centered for viewing.

Could you provide more measurements? Corner to bedroom door (I'm guessing standard 3 foot door), corner to closet door, width of closet door, corner to window, width of window. Is the closet door bi-fold or what?
Is your screen a commercial screen? Pull down? Retracted width?

I can model it up in Sketchup and show you what I come up with. I'm really liking your design, but I'm seeing it more as a cool headboard for your bed then a coffee table.

Yes that sounds like a great option because of the height you could obtain and the bulky heavy bits could even go under the bed. Excellent suggestion. I cannot wait to see the mockup.

Ok, so I'm fed up with my current apartment and have decided to move. I'm moving to a new apartment with similar dimensions but probably not exact... Looks like construction will be put on hold until the move, since I can't be sure how big my room will be, But we can still at least work on the design of the projector case and trunk/headboard/coffee table.

3' to the door from the corner, almost, but not quite 8' from corner to closet door. Closet has sliding double doors. No screen yet, but I was planning on using the flat white paint on the wall, or maybe some blackout cloth permanently fixed to one of the walls.


This is what I had in mind when I said that the whole projector would be tilted up slightly, which would fix the problem of having the projector in the way, but cause more keystoning problems. I have no idea if they would be fixable or not.

As you're moving, there's really no need to design for your current room.

What I was thinking for your current room was placing the bed against the left wall (in your floor plan image) and projecting towards your closet. Ideally, you could have a commercial pull down screen so that it doesn't interfere (having sliding doors would be best for this) with getting into the closet when you're not using the projector. You shouldn't have much trouble mounting the screen as you could probably get away with (seeing as you live in a rental) using those metal or wood angle brackets that one would use to hold a shelf up. When you moved, you could simply patch up the holes.

As far as tilting the projector, thats what most people do when they build a coffee table design. You'll just need to make sure you can manually adjust the keystoning in your projector. And keep in mind that you don't want to tilt it much more than about 15 degrees.